Embodiments of this application provide a direct current bus voltage control method and apparatus, and a power system, and relate to the field of electric power technologies, to quickly identify a voltage between an inverter circuit and an alternating current grid, so as to timely control a voltage of a direct current bus, thereby improving stability of the power system. The method includes: obtaining an electrical parameter between the conversion circuit and the direct current bus; generating a predicted voltage between the inverter circuit and the alternating current grid based on the electrical parameter and a voltage prediction model; and controlling a voltage between the conversion circuit and the direct current bus based on the predicted voltage.

A method of controlling a half-bridge circuit includes receiving an analog feedback signal proportional to an output of the half-bridge circuit, comparing the received analog feedback signal with a threshold value, selecting a digital feedback signal based on a result of the comparing, comparing the digital feedback signal with a digital reference signal to generate a digital error signal, integrating the digital error signal to generate an integration error signal, downscaling the integral error signal to generate a downscaled integration signal, sampling the downscaled integration signal to generate a sampled integration signal, and generating pulsed signals from the sampled integration signal to provide an input to the half-bridge circuit.

A control circuit for controlling a switching converter having a low quiescent current. The control circuit has an error amplifying circuit, an on time generator, a first comparing circuit and a second comparing circuit. When the switching converter operates in a light load operation mode, the error amplifying circuit and the on time generator are deactivated. Meanwhile, the first comparing circuit compares a current sensing signal indicative of inductor current with a current reference signal to provide an off time control signal during an on state of a low side switch to determine an on moment of a high side switch. The second comparing circuit compares the voltage feedback signal with a voltage reference signal to provide an on time control signal to determine an off moment of the high side switch.

An integrated circuit for a power supply circuit that generates an output voltage from an input voltage. The power supply circuit includes a transformer, a transistor controlling an inductor current flowing through a primary coil of the transformer, a first capacitor, and a first diode charging the first capacitor. The integrated circuit is configured to control switching of the transistor. The integrated circuit includes a first terminal configured to receive a voltage across the first capacitor; a second terminal configured to receive a feedback voltage corresponding to the output voltage; a driving signal output circuit configured to output a driving signal to increase a switching period of the transistor, in response to a decrease in a load current; a driver circuit configured to drive the transistor in response to the driving signal; and a determination circuit configured to determine whether the power supply voltage drops below a first voltage.

A switch-mode power supply includes a pair of input terminals for receiving an alternating current (AC) or direct current (DC) voltage input from an input power source, a pair of output terminals for supplying a direct current (DC) voltage output to a load, and a three-level LLC circuit coupled between the pair of input terminals and the pair of output terminals. The circuit includes a first switch coupled with a first diode to define a first half-bridge and a second switch coupled with a second diode to define a second half-bridge. The power supply further includes a third switch coupled across the first diode and the second diode to short circuit the first diode and the second diode when the third switch is closed, and a control circuit including a voltage-controlled oscillator (VCO), at least one flip-flop and multiple logic gates to operate the three switches with zero-voltage switching (ZVS).

A boost converter includes an input terminal, an output terminal, a switching terminal, a low-side transistor, and a down-mode detection circuit. The low-side transistor is coupled to the switching terminal. The down-mode detection circuit is coupled to the low-side transistor. The down-mode detection circuit is configured to detect a voltage at the output terminal greater than a voltage at the input terminal, and turn off the low-side transistor based on the voltage at the output terminal being greater than the voltage at the input terminal.

A system includes: 1) a battery configured to provide an input voltage (VIN); 2) switching converter circuitry coupled to the battery, wherein the switching converter circuitry includes a power switch; 3) a load coupled to an output of the switching converter circuitry; and 4) a control circuit coupled to the power switch. The control circuit includes: 1) a switch driver circuit coupled to the power switch; 2) a summing comparator circuit configured to output a first control signal that indicates when to turn the power switch on; and 3) an analog on-time extension circuit configured to extend an on-time of the power switch by gating a second control signal with the first control signal, wherein the second control signal indicates when to turn the power switch off.

A power converter includes a converter, an inverter, and a control unit. The converter converts electric power supplied from a power supply side to DC power. The inverter is provided on an output side of the converter. The control unit is configured to calculate a control difference between a target value for a target control voltage in a DC section provided on the output side of the converter and a feedback value using a DC voltage of the DC section as the feedback value, to perform a nonlinear operation process on the control difference, and to calculate an operation value based on a result of the nonlinear operation process and control the converter using the operation value.

In a switching power supply, a rectifying circuit outputs a first voltage. A switching circuit switches the first voltage into a switching voltage. An output circuit generates a second voltage based on the switching voltage. A feedback circuit generates the feedback signal based on the first and second voltages, and includes a carrier wave generation circuit that generates a carrier wave. The carrier wave has a non-linear shape at its rising edge and/or falling edge. A PWM circuit generates a PWM signal based on a comparison between the first voltage and a voltage of the carrier wave. Due to the non-linear shape, as the first voltage is higher, a pulse width of the PWM signal is changeable more greatly based on a change in the first voltage. A low-pass filter generates the feedback signal based on the PWM signal.

A voltage control apparatus includes a boost converter configured to convert an input voltage to a voltage equal to or higher than a first voltage in an operative state and directly output the input voltage in an inoperative state, a buck-boost converter coupled with the boost converter in parallel and configured to convert the input voltage to a second voltage lower than the first voltage, a memory, and a processor coupled to the memory and configured to keep the buck-boost converter in the operative state, set the boost converter to the inoperative state when the input voltage is equal to or higher than the first voltage, and change the boost converter to the operative state when the input voltage is lower than the first voltage.